Load page from button click JS

I know you can load a page view by using the events dropdown. I want to run a check on a text field though and load the page view as long as the user has typed something in it and prompt them to write something if they haven't.

I've looked through the iAd JS documentation but I find it very difficult to work with. I can't see where the code is that I need to reference a page and load it.

Can anyone help with that?

Thanks